Mercury – Water Separating Fuel Filter Kit | V6 & V8 FourStroke Series | Corrosion-Resistant Composite | 8M0135386

Overview

If you spend enough time on the water, you learn quickly that fuel quality can make or break a day. One little bit of moisture or debris is all it takes to throw off the rhythm of your engine. The Mercury Marine part 8M0135386 Water Separating Fuel Filter Kit is one of those pieces of gear that quietly earns your trust every time your boat starts clean and settles into that steady hum. It’s the kind of protection you feel — especially when you’re miles from shore and relying on your motor to carry you home without a hiccup.

Key Features

• High-capacity water separating fuel filter kit
• Designed for Mercury 3.4L V6 and 4.6L V8 175–300hp FourStroke outboards
• Transparent inspection bowl for immediate visual fuel checks
• Integrated drain for easy on-board servicing
• Water-in-fuel sensor compatible with all Mercury controls
• Marine-grade materials tested for heat, vibration, and salt exposure
• Engineered to remove moisture and debris before it reaches the engine

Engine & Boat Compatibility

• Mercury 175hp FourStroke
• Mercury 200hp FourStroke
• Mercury 225hp FourStroke
• Mercury 250hp FourStroke
• Mercury 300hp FourStroke
• Ideal for offshore center consoles, bay boats, pontoons, multi-species rigs, coastal cruisers, and heavier fishing boats

Performance & Practical Benefits

What sets this kit apart is how noticeably it improves engine consistency. When you’re running a big V6 or V8 outboard, the slightest bit of water in the fuel can cause hesitation, rough starts, or loss of power. This filter pulls moisture out before it ever has the chance to disrupt your day. You’ll feel the difference in how smoothly the engine accelerates, how steady it holds mid-range power, and how confidently it pushes your hull through chop.

The transparent bowl is a real-world advantage too — you can spot water or debris at a glance, without pulling anything apart. Draining it takes only a moment, and the sensor ties right into Mercury instrumentation, giving you an alert long before contaminated fuel becomes a problem. Everything fits tightly and cleanly, with that unmistakable OEM precision that makes maintenance faster and far less frustrating.

Whether your days on the water are about long runs, trolling, or cruising with the family, this filter keeps the fuel system protected so the engine can do what it was designed to do.

Why Buy OEM

Mercury’s fuel systems are built around specific tolerances, and OEM filtration is one area where cutting corners can cause real headaches. The 8M0135386 kit is engineered to match Mercury’s flow rates, pressure needs, and contamination standards. It lasts longer, seals better, and gives you peace of mind every time you turn the key. Buying OEM isn’t about badges — it’s about knowing your equipment is working with the engine, not against it.

FAQ

Q1: Which engines does this water separating fuel filter kit fit?

It fits Mercury 3.4L V6 and 4.6L V8 FourStroke outboards from 175 to 300 horsepower.

Q2: What makes this different from aftermarket filter kits?

OEM components fit more precisely, offer better moisture separation, and integrate with Mercury’s water-in-fuel sensor system.

Q3: How do I confirm this is the right kit for my motor?

Check your engine model and horsepower. If you run a 175–300hp FourStroke V6 or V8, this is the correct Mercury Marine part.

Q4: Can this be used in saltwater?

Yes — it’s designed specifically for harsh marine environments, including saltwater conditions.

Q5: Is installation easy for most boat owners?

Most owners find it straightforward, especially with the clear layout and accessible bowl design. Always follow your service manual.